Knee Cartilage Injuries
Knee cartilage injuries are a frequent cause of pain, swelling, and mechanical symptoms in people of all ages. The knee contains two distinct types of cartilage that serve different but equally important roles: articular cartilage and the menisci. Damage to either structure can disrupt normal joint function and increase the risk of long-term degeneration. At the OrthoIllinois Knee Center, comprehensive knee evaluation focuses on identifying the exact source of cartilage injury and developing a plan to protect joint health for patients throughout northern Illinois.
Articular cartilage is the smooth, white tissue that covers the ends of the bones inside the knee joint. It lines the femur, tibia, and the underside of the patella. Its purpose is straightforward but critical: it allows the bones to glide smoothly against one another while distributing weight evenly across the joint. Because it has no direct blood supply, it does not heal well once damaged. Even small areas of injury can gradually enlarge if stress continues on the joint.
Articular cartilage injuries may range from small surface cracks to full-thickness defects where cartilage is completely worn away, exposing underlying bone. When bone is exposed, pain typically becomes more persistent and activity-related discomfort increases.
The menisci are two C-shaped pieces of specialized cartilage located between the femur and tibia. Each knee has a medial meniscus on the inside and a lateral meniscus on the outside. Unlike articular cartilage, the menisci act as cushions and stabilizers.
The menisci help distribute body weight across the knee joint, improve stability, and protect the articular cartilage from excessive pressure. They also assist with shock absorption and joint lubrication.
Meniscal cartilage has a limited blood supply, primarily at its outer edge. Tears that occur in the outer region may have some healing potential, but tears in the inner portion generally do not heal on their own.
Damage to articular cartilage often causes:
- Activity-related knee pain
- Swelling that worsens after use
- Stiffness or reduced motion
- A grinding sensation with movement
Pain may be vague at first and develop gradually. Many people report discomfort when climbing stairs, squatting, or standing after prolonged sitting. Swelling may occur intermittently, especially after higher-impact activity. If the cartilage defect is larger, pain may become more constant. In advanced cases, symptoms may resemble early arthritis.
Meniscus injuries often present differently. Common symptoms include:
- Sharp pain along the inside or outside of the knee
- Swelling within 24 hours of injury
- Catching, locking, or clicking sensations
- Difficulty fully straightening or bending the knee
Meniscus tears frequently occur during twisting movements, especially when the foot is planted and the body turns. Athletes often describe a sudden pain followed by swelling. In older adults, meniscal tears may occur with minimal trauma due to age-related degeneration. Mechanical symptoms such as locking or catching are more common with meniscal injuries than with isolated articular cartilage damage.
Articular cartilage and meniscus injuries can occur separately or together.
- Acute trauma is a common cause. A direct blow to the knee, sudden pivoting during sports, or a fall can injure either structure. Ligament injuries, such as anterior cruciate ligament tears, are often associated with both meniscus and articular cartilage damage.
- Repetitive stress also plays a role. High-impact activity over time can gradually wear down articular cartilage. Alignment problems, such as bow-legged or knock-kneed positioning, increase uneven pressure and accelerate cartilage breakdown.
- Meniscal tears in younger individuals typically result from twisting injuries. In older adults, degenerative tears occur as the meniscus becomes less flexible and more prone to fraying.
- Age-related changes affect both types of cartilage. As cartilage thins and loses resilience, it becomes more vulnerable to injury even during routine movements.
Accurate diagnosis begins with a thorough medical history and physical examination. At OrthoIllinois Knee Center, physicians assess swelling, joint line tenderness, range of motion, and stability. Specific maneuvers can help identify meniscal tears or pinpoint areas of cartilage irritation.
X-rays are obtained first to evaluate bone alignment and check for signs of arthritis. Although cartilage does not appear directly on X-ray, joint space narrowing may suggest cartilage loss.
Magnetic resonance imaging (MRI) is the most useful tool for visualizing both articular cartilage and the menisci. MRI provides detailed images of soft tissues and can show the size and location of cartilage defects or meniscal tears.
In certain cases, diagnostic arthroscopy may be performed. This minimally invasive procedure uses a small camera inserted into the knee to directly inspect the joint surfaces and menisci. It allows precise evaluation and, when appropriate, treatment at the same time.
Cartilage injuries should not be dismissed as minor knee pain. Because articular cartilage does not regenerate easily and meniscus damage can accelerate joint wear, untreated injuries may progress to more serious joint degeneration.
Loss of meniscus function increases stress on articular cartilage. Over time, this added pressure can lead to cartilage breakdown and the development of osteoarthritis. Identifying and addressing these injuries early can help reduce long-term damage.
The OrthoIllinois Knee Center provides comprehensive knee care tailored to each patient’s age, activity level, and goals. As a leading bone and joint provider in northern Illinois, the focus is on restoring function while preserving the health of the knee joint.
With expert assessment and individualized care, many patients can reduce symptoms, improve stability, and protect the knee from progressive degeneration. Early attention to cartilage injuries is not optional if long-term joint preservation is the goal.
